Silicone compositions are known for use in waterproofing porous building materials, however, such compositions have generally involved relatively low molecular weight silicone fluids or oils. Such compounds are described, e.g., in Anderson, R. et al. (1987) "Silicon Compounds, Register and Review," Petrarch Systems, pp. 258-259. These oils, although waterproof, will dissolve and can be removed by appropriate solvents. They can even be physically forced from the pores by high pressure water. Such oils may also wick out of the pores and be absorbed by materials in contact with the impregnated substrate.
Examples of such prior silicone compositions are described in Linn U.S. Pat. No. 4,525,213 which discloses the use of low molecular weight (100-1000) alkylalkoxysilanes in non-alcohol-containing solvents for waterproofing concrete and masonry. These compounds react with the cement paste matrix of the substrate to form stable hydrophobic reaction products.
Seiler U.S. Pat. No. 3,772,065 describes alcoholic solutions of alkyltrialkoxysilanes and their lower oligomers as masonry impregnants.
Schmidt U.S. Pat. Nos. 4,517,375, 4,352,894 and 4,708,743 describe aqueous solutions of silanols prepared by hydrolysis of alkyltrialkoxysilanes as masonry waterproofing agents.
Boissieras et al. U.S. Pat. No. 3,444,225 describes organopolysiloxane derivatives ranging from mobile liquids to highly viscous oils which are stable in ambient air, and which are used as waterproofing and anti-adhesion agents.
Brady U.S. Pat. No. 3,304,318 describes a method for hydrolyzing alkoxysilanes to form siloxanes or silanols.
Hedlund U.S. Pat. No. 3,589,917 describes a method for preventing scaling and spalling of concrete comprising applying to concrete a silane of the formula QSiX.sub.3 wherein Q is a hydrocarbon or substituted hydrocarbon radical and X is a readily hydrolyzable radical, or an alkali metal monoalkyl siliconate having 1-4 carbon atoms in the alkyl group.
German Patent Application 2029446 discloses impregnating agents for masonry and inorganic oxides comprising solutions of alkyltrialkoxy silanes or their condensation products with 0 to 2 alkoxy groups per silicon atom in alcohols or hydrocarbons. This agent makes the masonry hydrophobic and preserves its ability to breathe, i.e., does not close the pores.
German Patent 1069057 discloses the use of water-soluble organosiloxanes for impregnating masonry to make it water-repellant, but able to breathe.
One-component room temperature vulcanizable rubber sealants have been known to the art since the 1960s. The Kirk Othmer Encyclopedia, under the Chapter Title, "Sealants," and Section Heading, "Silicones," discloses that these products have a Si-O-Si backbone and cure by exposure to moisture in the air.
One-component room temperature vulcanizable silicone rubbers are further described in the Kirk Othmer Encyclopedia under the Chapter Title "Silicon Compounds, Silicones," Section Heading, "Silicone Elastomers," as comprising fluids with silanol end groups which cure by reactions involving acetoxysilanes. The cure is brought about by contact with moisture in the air. Catalysts may be used to speed the reaction.
Anderson, R. et al. (1987) "Silicon Compounds, Register and Review," Petrarch Systems, pp. 258-259, at page 266 discloses that silanol terminated polydimethylsiloxanes with a molecular weight of 26,000 to 200,000 may be cross-linked with small quantities of multifunctional silanes which condense with the silanol groups. This reference discloses that such silanols are almost never used in fluid applications. The most commonly used multifunctional silanes used in one-component room temperature vulcanizable rubbers are acyloxy, enoxy and oxime silanes.
Product sheets from three compositions manufactured by Petrarch Systems disclose compositions which are silicone rubber compositions in nonaqueous volatile solvents which cure on contact with atmospheric moisture. However, these compounds all have a high percent solids (34% or more), and thus low concentration of volatile solvent (below 66%). These compositions are designed to form a protective film over the substrates rather than penetrate into pores thereof. Protection of the porous substrate using the compositions of this invention is 10 to 20 times better per weight percent solids than using the Petrarch compositions.
None of the foregoing patents disclose or suggest the use of one-component room temperature vulcanizable rubber intermediates in non-aqueous volatile solvents which cross-link in the presence of atmospheric moisture after application to porous materials such as masonry, wood or concrete to fill the pores and form a waterproof seal.